Generally, a light emitting diode is a typical light emitting device. The light emitting diode refers to a light emitting device for emitting excess energy as light when electrons and holes are recombined. The light emitting diode is being widely used in various fields such as a numeral/character displaying element, a signal light, a light source for a photo coupler and a display device.
Further, the following four conditions should be satisfied to manufacture the light emitting device in good quality. A first condition is a good luminance, a second condition is a long lifetime, a third condition is a thermal stability, and a fourth condition is a low voltage operation.
Among them, the luminance has a close relation to a consumption power. A variety of methods are being developed to currently increase the luminance of the light emitting diode.
Meanwhile, according to the trend of miniaturization and slimness of an information communication apparatus, a variety of parts of the apparatus such as a resistor, a condenser and a noise filter are being more miniaturized. Together with this, many attempts are being made to directly mount the light emitting device with a volume reduced, on the circuit board in a package format.
A related-art light emitting device package is described as an example.
In a structure of the related-art light emitting device package, an electrode lead frame is disposed at a body of the light emitting device package to apply a power source to a light emitting device from an external Printed Circuit Board (PCB).
A mold lens is attached to an upper portion of the package body to improve a luminous efficiency of an emission light of the light emitting device. Additionally, an assembly having the mounted light emitting device is engaged with a lower portion of the package body as below. First, a reflection cup having a high rate of light reflection is engaged to an upper portion of a conductor, and the light emitting device is mounted on a sub mount, which is formed of silicon, by a flip chip bonding or a wire bonding. After that, the sub mount is etched to provide a reflection groove part, and a reflection layer is formed on the reflection groove part. After that, the light emitting device is mounted.
However, the related-art package has a disadvantage in that a plurality of light emitting devices cannot be placed in a single package and a manufacture process is complex.
Another related-art light emitting device package is described.
A circuit board having the light emitting device package and a conductive wire is placed at an internal and lower side of a frame. The light emitting device package is panel-shaped. Additionally, an epoxy-molding layer is provided within the frame to disperse a light of the light emitting device package, and a diffusion plate is adhered to an upper portion of the frame. At this time, the diffusion plate and the light emitting device should be spaced apart from each other to increase a luminance. As such, the diffusion plate and the light emitting device package should be spaced apart and maintained at five or more millimeter. Therefore, the related-art light emitting device package has a drawback in that it is difficult to achieve lightweight, slimness and simplification of a panel.
The above-described related-art light emitting device package has a drawback in that in case where a magnitude of current is increased to obtain a high-power light, a high heat is generated due to a bad performance of a heat sink. Additionally, in case where the light emitting device package has the high heat as it is without dissipation, a resistance is much increased to reduce an luminous efficiency. Specifically, the related-art light emitting device package has a disadvantage in that since the conductor, the reflection cup, the package body and the like are separated from one another, the generated heat of the light emitting device is not easily transmitted to the exterior due to the existence of many thermal resistors.
Further, the related-art light emitting device package has a disadvantage in that since only one light emitting device is installed within the package body, three light emitting device packages should be operated as a set to embody a high-power white light. In this case, there is a disadvantage in that a control circuit is complex and a volume is increased.
Furthermore, since a total board area is increased in a single product type of a multi-combined light emitting device package to connect an electrode with the exterior, an assembly process is increased in cost.